Fig. 1

Roles of auxin and cytokinin in de novo root regeneration. A, B Phenotype (A) and adventitious rooting rate (B) of the detached Col-0 leaves treated with LOV. d, days. C Adventitious rooting rate of the detached leaves from Col-0, ahk2-2 ahk3-3 ahk4-1 (ahk2 3 4), and arr1-3 arr10-5 arr12-1 (arr1 10 12). Values shown are mean ± s.e.m. from three biological replicates (n = 30 in each replicate) (B, C). The experiment in (C) was performed together with the LOV treatment experiment in (B), therefore using the same control data, i.e. B5 in (B) and Col-0 in (C). D, E Expression patterns of DR5_pro:GUS (D) and ARR5_pro:GUS (E) in regeneration-competent cells at t₀, adventitious root founder cells at 2 days, adRP at 3 to 4 days, and adRAM at 5 to 6 days. F–H Results of the mPS-PI staining of the adventitious root tips from Col-0 (F), ahk2-2 ahk3-3 ahk4-1 (G), and arr1-3 arr10-5 arr12-1 (H). Black dots in the Col-0 columella represent starch grains (F). I, J Expression pattern of WOX5_pro:GUS in the adventitious root tips in the Col-0 (I) and arr1-3 arr10-5 arr12-1 (J) genetic backgrounds. K–M Expression pattern of J2341 in the adventitious root tips in the C24 (K), ahk2-2 ahk3-3 ahk4-1 (+ / −) (L), and arr1-3 arr10-5 arr12-1 (+ / −) (M) genetic backgrounds. AHK4-1 and ARR12-1 are heterozygous. The left panels present the J2341 fluorescent signals, whereas the right panels present the J2341 and PI fluorescent signals. N Model of the effects of auxin and cytokinin during the formation of the adRAM. RCC, regeneration-competent cells; adRFC, adventitious root founder cells; adRP, adventitious root primordium; RC, root cap; SCN, stem cell niche; V, vasculature; C, columella; CSC, columella stem cells; SCN, stem cell niche; adRAM, adventitious root apical meristem; CK, cytokinin; + / − , heterozygous. Scale bars, 2 mm (A) and 50 μm (D–M)